Children's Space Maintainer Guide: Protecting Room for Permanent Teeth After Early Baby-Tooth Loss

A space maintainer is a children's appliance that keeps the gap open until the permanent tooth below comes in, when a baby tooth has been lost earlier than its natural time to a cavity or injury. The 20 baby teeth act as guides for the permanent teeth, and if the gap is left as it is, neighboring teeth can tilt or drift in and reduce the space for the permanent tooth. It is not needed in every case, so the decision is made by looking at the position of the lost tooth, the child's age and how far the permanent tooth has developed on an X-ray.

Published 2026-11-08 · Updated 2026-11-08 · DentalStatics editorial team

Key facts

Number of baby teeth	20 (all in by age 2-2.5) (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청))
Guidance on when permanent teeth appear	Dental checkup recommended from around 54-65 months (source: Korea Disease Control and Prevention Agency (KDCA))
Target conditions of the infant oral checkup	Cavities (dental caries), gum enlargement, tooth abnormalities (source: National Health Insurance Service (NHIS, 국민건강보험공단))
Insurance principle for orthodontics	Non-covered (except notified cases such as cleft lip and palate treatment) (source: National Health Insurance Service (NHIS))
Outpatient copayment, ages 1 to under 6	70% of the standard patient copayment rate applies to insured care (source: Health Insurance Review and Assessment Service (HIRA, 건강보험심사평가원))

Why is a space maintainer needed?

Permanent teeth are growing beneath the baby teeth, and the baby teeth hold the space until those permanent teeth come up. In particular, if a baby molar is lost early, the molar behind it can tilt forward and narrow the space for the premolar that comes in later.

Once the space has shrunk, the permanent tooth may come in crooked or be trapped in the gum, and orthodontic treatment may be needed to create room again. A space maintainer is a preventive appliance that stops such changes ahead of time and helps the permanent tooth come in where it should.

In which cases is a space maintainer used?

Typical cases are when a baby molar with a large cavity that cannot be saved is pulled, or when a baby tooth is lost in a fall. Conversely, if the permanent tooth below has already risen close to the gum and is about to come in, the dentist may simply watch without an appliance.

The KDCA sees around 54-65 months as the time permanent teeth appear and recommends a dental checkup, so if a baby tooth is lost around this period, checking how far the permanent tooth has developed on an X-ray is the starting point for the decision.

If a space maintainer is chosen, the dentist also watches how the gap changes while the appliance is being made. Whether the impression is taken on the day of extraction or after the wound heals depends on the clinic and the condition of the teeth, so confirm the schedule in advance.

Whether the lost baby tooth is a front tooth or a molar
How far the permanent tooth below has grown and when it will come in
Whether several molars on both sides have been lost
Whether the child is old enough to look after the appliance

What types of space maintainers are there?

A typical type is a fixed appliance in which a band is attached to a neighboring tooth and a wire holds the gap. If molars on both sides are lost, an appliance connecting left and right with a wire may be used, and when several teeth are lost, a removable appliance that the child can put in and take out is considered.

A fixed appliance has no risk of the child removing and losing it, but the area around it may be hard to clean, while a removable appliance is easy to clean but works only if the child wears it consistently. Which form suits depends on the position of the lost tooth and how well the child cooperates.

What is checked while the appliance is in place?

The appliance is checked regularly while confirming that the permanent tooth is coming up. When the permanent tooth below starts to break through the gum, the appliance is removed, and if the timing is missed the appliance can block the path of the permanent tooth, so keeping appointments is important.

Sticky candy, caramel and hard ice can cause the appliance to come off or the wire to bend. If the appliance becomes loose or the wire pokes the gum, contact the dental clinic right away, and clean carefully around the band, where cavities form easily.

How do you check the cost of a space maintainer?

The cost of a space maintainer varies greatly with the type, the way it is made and the clinic. National Health Insurance medical care benefit standards treat orthodontics as non-covered in principle, so it is best to have each item explained before treatment, including whether the appliance cost is covered.

Besides making the appliance, care such as an examination, X-rays and baby-tooth extraction may be done together, and the insured items among these receive an age-based reduction in the copayment. Looking at the insured and non-covered columns of the receipt separately shows the exact cost of the space maintainer itself.

Whether the appliance cost includes regular checks and adjustments
The cost of re-cementing if the appliance comes off
The cost of removing the appliance when the permanent tooth comes in

Common myths and facts

Myth: Baby teeth fall out anyway, so losing one early is no problem.

Baby teeth hold space for permanent teeth. If one is lost earlier than its natural time, neighboring teeth can tilt and reduce the space for the permanent tooth.

Myth: A space maintainer is always needed after a baby tooth is pulled.

If the permanent tooth below is about to come in, or for a spot such as a front tooth where space changes less, the dentist may watch without an appliance. The decision is made by looking at the permanent tooth on an X-ray.

Frequently asked questions

How long is a space maintainer worn?

It is worn until the permanent tooth below begins to come in. This varies from a few months to several years depending on when the tooth was lost and how the permanent tooth develops, and the removal time is set by checking the position of the permanent tooth on X-rays taken at regular checks.

Does a space maintainer hurt or make speaking uncomfortable?

There may be a foreign-body feeling for the first few days, but most children soon get used to it. If the wire presses on the gum or causes a sore, get it adjusted.

The appliance came off. Can it just be recemented?

Do not throw away an appliance that has come off; bring it with you. If its condition is good it can be recemented, but if it is bent or does not fit, a new one may need to be made.

If a space maintainer is used, will orthodontics be unnecessary later?

A space maintainer keeps the space that would shrink, but it does not straighten the whole dental arch. Problems that come from a mismatch between jaw size and tooth size may need a separate orthodontic consultation.

Is an appliance needed if a front baby tooth is lost early?

Some consider that space changes less at a front tooth than at a molar, so an appliance is sometimes not used. However, an appliance is sometimes discussed for speech or appearance reasons, so it is decided to suit the child's situation.

References

Korean version →